Four suspected of plotting terrorist attack arrested in London

Four men have been arrested in east London over an alleged terror plot on United Kingdom soil, police have said.

The men, aged between 18 and 27, were arrested at their homes in east London on Wednesday on suspicion of "the commission, preparation or instigation of acts of terrorism", the Metropolitan Police said in a statement.

The operation followed heightened activity by counter-terrorism investigators that led to the thwarting of two alleged plots last month in London.

Officers from the Met's crack Counter Terrorism Command swooped on four locations this morning, but Scotland Yard didn't specify exactly where in east London.

The police force says the arrests are linked to activity in the United Kingdom, but has not revealed details of the alleged plot.

A day before, police arrested an individual carrying knives near Downing Street - the London residence of the prime minister.

The current terror threat level in the United Kingdom is severe, the second highest, which means an attack is highly likely.